Steel sucker rods have been used for decades in producing oil wells to actuate petroleum pumps, located in a well bore of a producing, but not pressurized oil well. A series of sucker rods are connected together to form a string extending down into the well bore and are connected to the petroleum pump at one end and to a cyclic or reciprocating drive mechanism at the well head to actuate the petroleum pump to cause oil to be pumped up the well bore and into a pipe line.
Steel sucker rods providing tensile strength to withstand thousands of cyclic axial forces are inherently heavy, thereby requiring a sizable reciprocating drive mechanism at the well head to effectively actuate the pump down in the well bore, which, of course, requires more energy to operate. In addition, the corrosive effects of steel contributed significantly to the cost of oil production, in that steel sucker rods had to be replaced periodically.
It is therefore an object of the present invention to provide a sucker rod construction of considerably less weight than its all-steel counterpart, thereby requiring less energy to operate.
It is another object of the present invention to provide a sucker rod construction having improved corrosion resistant characteristics, thereby greatly extending the useful life thereof.
It is a further object of the present invention to provide an improved sucker rod construction having improved elasticity characteristics, resulting in increased efficiency.